其他凝聚态物理

In this paper we use the important interferences of Macro-Orbital theory of superfluidity clubbed with several factors that can change the rotational constant (B) and vibrational frequency of N2O in 4HeN-N2O clusters with N to account for…

With an eye on plasma walls we investigate, within an effective model for the two active electrons involved in the process, secondary electron emission due to Auger de-excitation of metastable nitrogen $N_2(^3\sigma^+_u)$ molecules at…

Earlier, the magnetoelectric effect of chromium sesquioxide Cr_2O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2O_3 crystals or the magnetic field-induced…

In a system containing a large number of interacting stochastic processes, there will typically be many non-zero correlation coefficients. This makes it difficult to either visualize the system's inter-dependencies, or identify its dominant…

We simulate a trapped quasi-two-dimensional Bose gas using a classical field method. To interpret our results we identify the uniform Berezinskii-Kosterlitz-Thouless (BKT) temperature $T_{BKT}$ as where the system phase space density…

The diffusion characteristics of stable aqueous dispersion of "single-nano buckydiamond" concentration 80 mg/ml, average particle size 8 nm and pure water as the reference system were investigated by quasielastic neutron scattering. The…

We have re-examined the Andreev-Lifshitz theory of supersolids. This theory implicitly neglects uniform bulk processes that change the vacancy number, and assumes an internal pressure $P$ in addition to lattice stress $\lambda_{ik}$. Each…

Using Andreev and Lifshitz's supersolid hydrodynamics, we obtain the propagating longitudinal modes at non-zero applied pressure $P_{a}$ (necessary for solid 4He), and their generation efficiencies by heaters and transducers. For small…

We have applied the Andreev-Lifshitz hydrodynamic theory of supersolids to an ordinary solid. This theory includes an internal pressure $P$, distinct from the applied pressure $P_a$ and the stress tensor $\lambda_{ik}$. Under uniform static…

A robust thermodynamic argument shows that a small reduction of the effective coupling constant $\alpha$ of QED greatly enhances the Compton scattering cross section and that the Thomson scattering length is connected to a fundamental scale…

Building on a general variational framework for multi-fluid dynamics, we discuss finite temperature effects in superfluids. The main aim is to provide insight into the modelling of more complex finite temperature superfluid systems, like…

A introduction into density-functional theory and electronic structure methods is given, that aims at providing an intuitive understanding of the underlying concepts for the novice as well as an entry point towards the more advanced…

We present results from a detailed Quantum Monte Carlo study of BEC applied to JILA experiment [Jin et al Phys. Rev. Lett. $\bf 78$, 764, 1997][1]. This is the first Monte Carlo approach(based on Feynman-Kac path integral method) to the…

To address the impact of electron correlations in the linear and non-linear response regimes of interacting many-electron systems exposed to time-dependent external fields, we study one-dimensional (1D) systems where the interacting problem…

We construct numerical basis function sets on a lattice, whose spatial extension is scalable from single lattice sites to the continuum limit. They allow us to compute small and large bound states with comparable, moderate effort. Adopting…

We define the "BEC state" to be the many-body wavefunction where all particles are in the same one-body state. Using an argument analogous to Anderson's Orthogonality Catastrophe, we argue that for interacting particles the amplitude of the…

Through the exact solution of a two-electron system interacting with a monochromatic laser we prove that all adiabatic density functionals within time-dependent density-functional theory are not able to discern between resonant and…

We obtained new nonrelativistic expression for the dynamical van der Waals atom -surface interaction energy of very convenient form for different applications. It is shown that classical result (Ferrell and Ritchie, 1980) holds only for a…

We calculate intensity of radiative heat transfer and radiative conductance in a system of two spherical particles embedded in equilibrium vacuum background (photon gas). The temperatures of the particles and of the background radiation are…

We present the results of new experiments on the observation of the electric response of superfluid helium (He II) at the excitation of second-sound waves in it. We used an acoustic resonator with dielectric case, in which the measurements…